ANALYSIS OF CYCLONE SEPARATOR USING CFD METHODOLOGY

Abstract

The Particulate Matter is the most crucial parameter which decides the pollution level in air. The negative impact of particulate matter is solely because of its submicron size which causes bad effects on human. There are many air quality control devices available which separates out the particulate matter using different sets of principles. Cyclone Separator is a type of air quality control device which uses physical phenomenon of centrifugal acceleration. The efficiency of cyclone separator to eliminate particulate matter is average as compared to other devices and techniques but its cost efficiency is quite high due to its basic working principle and no moving parts. The polluted air enters tangentially from the inlet and descends in swirling pattern in the hollow cylinder and cone parts of the cyclone body. This spiral motion of particle laden air produces a centrifugal force on the particles and pushes them towards wall of the cyclone. Therefore, the designing and analysis of cyclone separator is difficult due to complex flow pattern. Pressure drop and different velocities generated through cyclone body is the most important parameter to predict its performance. Many studies and research work have been done in the field of cyclone separator but there are no specific techniques and empirical formulas to analyse the flow pattern and pressure drop. Solving the flow and particle transport equations using CFD (Computational Fluid Dynamics) approach is one of the method that can be followed with specific sets of equations and model. The present study is carried out to analyse the performance of three models of cyclone separator with different vortex finder diameter using RSM (Reynolds stress model) methodology to predict turbulent flow behaviour and DPM (Discrete phase model) to trace the particles trajectories through each cyclone model. The equations are solved computationally using the CFD based software FLUENT (v18.2). The case in the study is computed using an assumption of one-way coupling in the cyclone separator. The graphs and contours of velocities and pressure drop are analysed and compared to study the effect of varying diameter of vortex finder. Collection efficiency is determined by injecting a fixed number of particles from inlet and counting the trapped particles.